Remote battery disconnect for a DC battery - KiloVault HAB 7.5

[budgetsolarinstall]

“The inspector asked about the battery. He may require a remote battery disconnect. I'm not having any luck w Kilovault. Their battery has a breaker disconnect and the Solark has a breaker disconnect.

Our plans they approved do not show an external battery disconnect. And they approved the plans and issued us the permit.

Vermont does not require this but I don't know NH inspector and since it's in the city they may be sticklers.

Battery remote disconnect. The disconnect mounts outside near the other disconnects but is low voltage control wire such as cat6 to the battery.

I use battery cable disconnects near the battery no problem, cable to cable.

This would be something with low voltage wires. We don't use them here in VT but NH may be different.”

Does anybody have any suggestions?

I think the inspector is confusing an “AC coupled” battery solution like Tesla power wall with a DC battery system. The Tesla power wall is its own system, and I guess it makes sense to have a remote disconnect switch for it.

 

[pvgirl]

Point out the sol-ark's emergency stop/rsd input will completely shut down the inverter, turn off all outputs, which functionally disconnects the battery from the load(the house). Put an an emergency stop switch near the other disconnects, if you don't already have one.

 

[budgetsolarinstall]

Point out the sol-ark's emergency stop/rsd input will completely shut down the inverter, turn off all outputs, which functionally disconnects the battery from the load(the house). Put an an emergency stop switch near the other disconnects, if you don't already have one.

Is this additional emergency stop switch usually a part of regular installs with the sol ark?

 

[pvgirl]

Is this additional emergency stop switch usually a part of regular installs with the sol ark?

It's usually used when rapid shutdown of PV is handled by the sol-ark. The same emergency stop is used for both rapid shutdown, and shutting down the inverter. In cases where rapid shutdown isn't needed or is handled by something other then the sol-ark, the switch isn't normally installed. But can be add as it is a simple 2 wire low voltage connect to an external switch, for case where local requirements, or AHJ want a simple shutdown of the energy storage system.

 

[TomC4306]

Midnite Solar has remote trip breakers for this.

Product - MidNite Solar

MidNite Solar Product Page.

www.midnitesolar.com

 

[budgetsolarinstall]

It's usually used when rapid shutdown of PV is handled by the sol-ark. The same emergency stop is used for both rapid shutdown, and shutting down the inverter. In cases where rapid shutdown isn't needed or is handled by something other then the sol-ark, the switch isn't normally installed. But can be add as it is a simple 2 wire low voltage connect to an external switch, for case where local requirements, or AHJ want a simple shutdown of the energy storage system.

The actual switch which goes outside - can someone provide a link for that please? My installer can’t find it because nobody does it in VT.

 

[pvgirl]

Here is an example of one that will work: https://www.solar-electric.com/imo-bg10p34-11-emergency-stop-pushbutton.html
These are common industrial parts, and other options may available locally. Any emergency stop button with a normally open contact will work.

 

[fmeili1]

I've installed a 600Amp 80VDC relay for each of my battery racks filled with 5kWh 48V LiFePO4 batteries. These are usually used for golf carts and not very expensive. Btw. If these relays are already installed with an emergency shutdown switch, it would be easy to add additional functionality, e.g. a WiFi remote relay and/or a smoke detector relay, etc. to also be able to disconnect the battery - just in case.
I've bought here for $63 each.

 

[budgetsolarinstall]

Here is an example of one that will work: https://www.solar-electric.com/imo-bg10p34-11-emergency-stop-pushbutton.html
These are common industrial parts, and other options may available locally. Any emergency stop button with a normally open contact will work.

Thanks! The installer is asking what type of cable should be used.

 

[pvgirl]

It’s a low voltage signaling circuit, you could use doorbell, in wall speaker, or thermostat wire, most anything with 2 conductors and rated for use in a wall will work.

 

[budgetsolarinstall]

In the meantime, just spoke with Sol Ark support. They clarified that the need for this emergency stop button is being seen in many states because when the house is burning firefighters need to ensure that the inverter is not doing any conversions within it.

Also, this does not trip any breakers (my installer question).
It just shuts down the inverter entirely.

Everything else they told me - already mentioned above by @pvgirl

Note that they never indicated the need for this button during the permitting process. Last minute thing inspector called and told my installer.

Thank you sooooo much everyone! Fingers crossed for the inspection.

 

[slik056]

Point out the sol-ark's emergency stop/rsd input will completely shut down the inverter, turn off all outputs, which functionally disconnects the battery from the load(the house). Put an an emergency stop switch near the other disconnects, if you don't already have one.

This is not a solution unfortunately, due primarily to a pretty substantial design fault with Sol-Ark. It also does not meet the NEC 480.7 requirements that the inspector is likely referencing (albeit they may be stretching the requirement since technically it only applies when batteries are >60V, and the common compatible lithium options will only get to about 57.6V maximum). Anyway, the issue is that when the Sol-Ark RSS trigger contacts re-open on the Sol-Ark, the inverter will boot right back up and start producing power again. Hence if the trigger wiring from the remote shutdown device is compromised (say during a fire or when first responders are overhauling the building), this would result in the inverter re-energizing the backup power outputs and could potentially electrocute a first responder. I have discussed this at length with Sol-Ark, and my suggestion was to force the inverter into a lockout until the inverter is manually reset, since this would be a relatively simple firmware modification, but to date no solution has been implemented. The right way to deal with the NEC requirements that are spreading around the US and being applied by certain utilities now as well regarding the breaking of the DC battery conductors even when <60V, would be to have Sol-Ark install a shunt trip on the input breakers that trips when the RSS wires are triggered, thus physically opening the breaker remotely, and alleviating the need to piecemeal 3rd party solutions that are often not NRTL listed. As an installer I would happily pay a reasonable premium for this feature since it is mandated not by the AHJ's, but by the utilities themselves out here as part of the interconnection agreement. Until then... separate enclosures with high amperage shunt trip breakers is the painful solution...

 

[pvgirl]

This is not a solution unfortunately, due primarily to a pretty substantial design fault with Sol-Ark. It also does not meet the NEC 480.7 requirements that the inspector is likely referencing (albeit they may be stretching the requirement since technically it only applies when batteries are >60V, and the common compatible lithium options will only get to about 57.6V maximum).

That requirement clearly doesn't apply to the sol-ark as it won't be used with batteries greater then 60 volts.

Your point point about circuit integrity on rapid shutdown circuits, is definitely a valid one, and one that is not limited to just sol-ark.

 

[pvgirl]

Anyway, the issue is that when the Sol-Ark RSS trigger contacts re-open on the Sol-Ark, the inverter will boot right back up and start producing power again. Hence if the trigger wiring from the remote shutdown device is compromised (say during a fire or when first responders are overhauling the building), this would result in the inverter re-energizing the backup power outputs and could potentially electrocute a first responder. I have discussed this at length with Sol-Ark, and my suggestion was to force the inverter into a lockout until the inverter is manually reset, since this would be a relatively simple firmware modification, but to date no solution has been implemented. The right way to deal with the NEC requirements that are spreading around the US and being applied by certain utilities now as well regarding the breaking of the DC battery conductors even when <60V, would be to have Sol-Ark install a shunt trip on the input breakers that trips when the RSS wires are triggered, thus physically opening the breaker remotely, and alleviating the need to piecemeal 3rd party solutions that are often not NRTL listed. As an installer I would happily pay a reasonable premium for this feature since it is mandated not by the AHJ's, but by the utilities themselves out here as part of the interconnection agreement. Until then... separate enclosures with high amperage shunt trip breakers is the painful solution...

One other option would add a relay and button at the sol-ark that will hold the RSD input closed when the e stop is activated, and only open when the button is pressed to reset the relay circuit. Fancy option would be to use an industrial control safety relay module, which could add some circuit protections to the estop wiring.

Also seems weird that the utilities are setting requirements beyond disconnects from there grid.

 

[Quattrohead]

I think you might be out of luck with the Kilovault batteries, the manuals I just looked at do not show any RSD type functionality.
Look at the EG4 PowerPro documentation, they have a separate pair of contacts specifically for this.
However, maybe some "education" of all parties involved will allow you to install these batteries this year....in the future a common RSD for panels, inverters and batteries is going to be required.

 

[Quattrohead]

I've installed a 600Amp 80VDC relay for each of my battery racks filled with 5kWh 48V LiFePO4 batteries. These are usually used for golf carts and not very expensive.

This will never fly for an inspected system.

 

[Quattrohead]

Anyway, the issue is that when the Sol-Ark RSS trigger contacts re-open on the Sol-Ark, the inverter will boot right back up and start producing power again. Hence if the trigger wiring from the remote shutdown device is compromised (say during a fire or when first responders are overhauling the building), this would result in the inverter re-energizing the backup power outputs and could potentially electrocute a first responder.

I'm not doubting you but....are you sure about this.
Surely when the inverter has been tripped off, there is no 12v to allow the RSD to turn the inverter back on again, even if the RSD switch is reset.
And I think, it is a normally closed switch to allow the inverter to run, hence if the control wire is compromised open, the inverter cannot turn on again.
At least, this is how Luxpower/EG4 work.

 

[pvgirl]

At least, this is how Luxpower/EG4 work.

How do these handle recovery for rapid shutdown? Lets say the emergency stop switch was pressed and the inverter shut down, after the emergency stop switch is reset, is there a manual reset, or other process to get the inverter going again?

 

[Quattrohead]

I am not sure, I will check it out next time I have to power cycle my system which hopefully won't be for a very long time.

 

[fmeili1]

This will never fly for an inspected system.

Why do you think this will be a problem?

I've implemented a safety addon which will disconnect all 3 energy sources (battery, PVRSS via Tigo, AC-in for battery charging) from the AIO inverters in case of smoke detection over the AIO's. I've done this to be able to sleep well with my DIY system and I want to use it even if I will be out for e.g. a longer vacation...

This goes far beyond what is required in even the newest NEC requirements. I live in Arizona, which still relies on NEC 2008 which don't even require PVRSS. I would have thought that would make the inspector more positive.

I would not understand why 3 additional safety features against fire would cause additional problems during inspection?

 

[Quattrohead]

Because it is not a manufacturer built, inspected and UL approved device or product so therefore it will never pass any safety inspection.
I am not saying what you did is wrong or rubbish, in fact you have all your bases covered and you are happy so it is all good. I'm just saying it's not official and all inspectors care about is covering their arse with someone else's approved documentation.

 

[fmeili1]

Because it is not a manufacturer built, inspected and UL approved device or product so therefore it will never pass any safety inspection.
I am not saying what you did is wrong or rubbish, in fact you have all your bases covered and you are happy so it is all good. I'm just saying it's not official and all inspectors care about is covering their arse with someone else's approved documentation.

My system is designed completely non-grid-interactive (like a "generator" solution with a manual - open transition type - transfer switch). I have the design approval from Unisource Energy for my DIY "generator" solution and I also have the building permit from the city for my DIY "solar generator" solution design with optional AC-in grid battery charging (no energy will feed back to the grid).

By end of the year, I hope I will have been finished all the remaining installation steps (there are still no PV modules installed because it's still too hot here to work on the roof). Than I have to schedule the inspection from the cities building department. I hope they will be tolerant because the additional, smoke detector controlled contactors, will add additional safety - independent of UL approved components. The utility company and the cities building department know that this is a 100% DIY project and approved it.

We will see how this ends...

 

[budgetsolarinstall]

This is the reply from KV support:

"As for remote disconnect, you can use the mid nite solar remote trip breaker, link below.

https://www.altestore.com/store/enc...rom=search&i=830cfc8141feab7db5a075d478c58c3a"

I spoke to Mid Nite support about this product, and they were aware that this could be used with the KV HAB.

My installer is familiar with this, but wanted to know whether it would work with the emergency stop button - Mid Nite confirmed it could be. This is what they said:

- It has a large handle which sticks out; use that to turn on or off.
- Two small wires come out of the back; hook up a signal to it, to trip the breaker.
- 12V is needed to trip the breaker.
- When I asked about the exact connection details for the stop button, they mentioned something about a pulse signal with a certain millisecond rate to trigger the on/ off.

Would be nice to get some comments from people who know about this setup.

 

[pvgirl]

Use a 48v to 12v volt converter on the inverter side of the breaker. Connect the 12volt output in series with a NO contact on the Emergency stop switch, and the remote trip wires on the breaker. This will make it so when the estop is pressed 12v from the 48v to 12v converter will flow to the remote trip on the breaker, causing it to open.

 

[budgetsolarinstall]

We passed the inspection and we are producing 1kW even in the shade! Thanks everyone for your help.